Electrically heating molten glass



Feb. 6, 1940-. e. SLAYTER 2,188,927

ELECTRICALLY HEATING MOLTEN GLASS Original Filed' March 3, 1955' INVEN TOR. GAME8 SLAYTER.

ATTOR EYS.

Patented Feb. 6,1940

-UNITED STATES PATENT OFFICE ELECTRICALLY HEATING MOI-TEN GLASS Games Slayter, Newark, Ohio, assignor, by mesne assignments, to Owens-Corning Fiberglas Corporation, a corporation of Delaware Substitute for abandoned application Serial No.

659,453, March 3, 1933. This application February 26, 1938, Serial No. 192,688

12 Claims. (Cl. 49-55) This application is a substitute for application trodes are formed with opposite recesses l which No. 659,453, filed March 3, 1933. together form an approximately circular channel My invention relates to apparatus for electrithrough which the glass flows in a continuous cally heating and controlling the temperature of stream from the outlet l2. The electrodes I3 5 a stream of molten refractory material such as provide a bushing for the outlet, being directly 5 glass, furnace slag or the like. beneath the container and in register with the An object of the invention is to provide a outlet so that the well I I and electrodes together practical means for heating a small stream of form a conduit through which the glass flows. such refractory material to a high temperature The electrodes may be made of any suitable conadapting it to the manufacture of fine wool. A ducting material which will withstand the high 1 method in commercial use at the present time temperature and corrosive action of the glass. for making glass wool consists in passing a small I find that wrought iron is suitable material for stream of molten glass through a blower by this purpose. which steam or other gas it blown against the The electrodes are supported by-a cylindrical glass with sufficient force to draw the glass into casing l6, said casing being made of semi-cylin- 15 threads or filaments which are accumulated to drical sections secured together by bolts H. The form a mass of glass Wool. The coarseness or upper end of the casing is flanged and connected fineness of the wool produced in this manner deby means of bolts l8 to a supporting structure pends to a large extent upon the temperature of I9. Insulating material is placed within the 20 the glass when it enters the blower. If the glass casing l6 and surrounds and encloses the elec- 20 is comparatively cold, the individual threads or trodes l3. This insulating material in the form filaments of the glass wool will be correspondshown consists of refractory blocks shaped to ingly coarse. By raising the temperature, a finer conform to the electrodes and the surrounding product is produced. The present invention procasing. Electric cables 2| and 22 are connected 25 vides suitable means for heating the flowing to the electrodes and extend therefrom to any 25 glass to a very high temperature which enables suitable source of electric current.

the production of a very fine glass wool. As is well known, the electrical resistance of Other objects of the invention will appear glass decreases as the temperature rises, so that hereinafter. molten glass is a comparatively good conductor of In the accompanying drawing: electricity. The stream of glass flowing down- 30 Fig. 1 is a sectional elevation of an apparatus ward from the outlet I2 between the electrodes adapted for making glass wool in accordance thus provides a conductor permitting a flow of with the present invention; current therethrough. The volume of this cur- Fig. 2 is a section at the line IIII on Fig. 1. rent depends upon the difference of potential showing the electrodes and their mounting; between the electrodes and the temperature of 35 Fig. 3 is a sectional elevation of a modified the glass flowing therebetween. Assuming that construction; and a flow of glass between the electrodes has been Fig. 4 is a section at the line IV-IV on Fig. 3. initiated and an electro-motive force impressed Referring to the drawing, a glass furnace tank at the electrodes, a flow of electric current through 0 5 provides a continuous supply of molten glass the glass will take place and cause the tempera- 40 6 which flows from the tank into a forehearth ture of the stream of glass to rise. If the voltextension 1 provided with an outlet opening 8 age at the terminals remains constant the volume extending through the floor thereof. The glass of current flow will increase as the temperature flows from the outlet in a continuous stream of the glass rises, causing a further rise in teminto an auxiliary tank or container 9. The rate perature due to the increased amperage. In this 45 of flow may be adjustably regulated and conmanner, the glass may be raised to a very high trolled by a vertically adjustable plug 10. The temperature. By regulating the voltage and amcontainer 9 is formed with a well ll extending perage, any desired high temperature of the through the floor of the container and having a stream of glass may be maintained.

bottom outlet l2. The stream of glass 23 flows downward from so Beneath the container 9 is a pair of electrodes the electrodes and is directed into and through l3 which, as shown in Fig. 2, are approximately a blower 24 which may be of conventional form. semi-circular in cross-section and are separated Steam is supplied to the blower through a pipe by an air space l4 by which they are insulated 25 and is caused to impinge upon the stream 5 from each other. The inner faces of the elecof glass and draw it out into fine filamentary form. The flberized glass is carried downward in the blast 26 of steam or other gaseous vehicle and accumulated on a continuously traveling conveyor 21 in the form of wool and conveyed to apparatus for further treatment.

Figs. 3 and 4 illustrate a modification in which the electrodes l3 are mounted directly beneath the outlet in the forehearth 1, the auxiliary receptacle 9 being omitted. In this construction the cylindrical casing l6 and the insulating material are also omitted. The electrodes are held in position by brackets 28.

Modifications may be resorted to within the spirit and scope of my invention.

I claim:

1. The combination of a container for molten glass consisting of electrically insulating refractory material and having an outlet opening through which a stream of glass issues, a pair of electrodes positioned beyond the container and spaced apart and shaped to provide a channel therebetween, said channel being in register with said outlet and providing a passageway through which the stream of glass flows, refractory insulating material surrounding and enclosing the electrodes, and a case surrounding and enclosing said electrodes and insulating material.

2. The combination of a container for molten glass, the bottom and walls of the container consisting of electrically insulating, refractory material, said bottom having an oulet through which the glass issues, a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal sections spaced a short distance apart, said electrodes being positioned beneath the said outlet and in register therewith and providing a vertically disposed channel through which flows a stream of glass issuing from said outlet, said channel having substantially the same cross-sectional area as the stream flowing therethrough, and means for supplying an electric current to said electrodes and causing it to pass therethrough and through the stream of glass flowing through said channel.

3. The combination of a container for molten glass, the bottom and walls of the container consisting of electrically insulating, refractory matei'ial, said bottom having an outlet through which the glass issues, a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal sections spaced a short distance apart, said electrodes being positioned beneath the said outlet and in register therewith and providing a vertically disposed channel through which flows a stream of glass issuing from said outlet, said channel having substantially the same cross-sectional area as the stream flowing therethrough, means for supplying an electric current to said electrodes and causing it to pass therethrough and through the stream of glass flowing through said channel, and a cylindrical refractory bushing of insulating material surrounding and enclosing said electrodes.

4. The combination of a container for molten glass, the bottom and walls of the container consisting of electrically insulating, refractory material, said bottom having an outlet through which the glass issues, a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal sections spaced a short distance apart, said electrodes being positioned beneath the said outlet and in register therewith and providing a vertically disposed channel through which flows a stream of glass issuing from said outlet, said channel having substantially the same cross-sectional area as the stream flowing therethrough, means for supplying an electric current to said electrodes and causing it to pass therethrough and through the stream of glass flowing through said channel, a cylindrical refractory bushing of insulating material I surrounding and enclosing said electrodes. a casing surrounding said refractory bushing, and means for securing said casing in position beneath said container and supporting said bushing and electrodes.

5. The combination of a pair of electrodes formed with opposite recesses which together provide a channel of substantially uniform crosssectional shape and area throughout its length, the length of said channel being at least several times as great as its greatest diameter, through which channel a stream of molten glass is caused to flow, and means for supplying electric current and causing it to pass from one to the other of said electrodes through the glass flowing in said channel.

6. The combination of a pair of electrodes formed with opposite recesses which together provide a channel of substantially uniform crosssectional shape and area throughout its length, the length of said channel being at least several times as great as its greatest diameter, through which channel a stream of molten glass is caused to flow, and means for supplying electric current and causing it to pass from one to the other of said electrodes through the glass flowing in said channel, the electrodes being spaced apart at opposite sides of the channel and thereby providing air spaces between the electrodes, said air spaces forming lateral extensions of said channel.

'7. The combination of a pair of electrodes formed with opposite recesses which together provide a channel of substantially uniform crosssectional shape and area throughout its length, through which channel a stream of molten glass is caused to flow, and means for supplying electric current and causing it to pass from one to the other of said electrodes through the glass flowing in said channel, refractory insulating material surrounding and enclosing the electrodes, and a case surrounding and enclosing the electrodes and insulating material.

8. The combination of a vertically disposed conduit through which a stream of molten glass is caused to flow downward, said conduit comprising an upper section of refractory material and an adjoining section therebeneath of elec trically conducting material, said last mentioned section consisting of a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal halves spaced 3, short distance apart, the length of said cylinder being much greater than its diameter, and means for supplying electric current to said electrodes and causing it to pass therethrough and through the stream of glass as the latter flows between the electrodes.

9. The combination of a vertically disposed conduit through which a stream of molten glass is caused to flow downward, said conduit comprising an upper section of refractory material and an adjoining section. therebeneath of electrically conducting material, said last mentioned section consisting of a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal halves spaced a short distance apart, the length of said cylinder being much greater than its diameter, means for supplying electric current to said electrodes and causing it to pass therethrough and through the stream of glass as the latter flows between the electrodes, and a cylindrical refractory bushing of insulating material surrounding and enclosing the electrodes.

10. The combination of a conduit through which molten glass is caused to flow, said conduit comprising a section of refractory material and an adjoining section of electrically conducting material, said last mentioned section consisting of a pair of electrodes in the form of a cylinder split longitudinally to provide separate longitudinal halves spaced 2. short distance apart, said conduit being vertically disposed to permit a stream of molten glass to flow therethrough, means for supplying electric current to said electrodes and causing it to pass therethrough and through the stream of glass as the latter flows between the electrodes, a cylindrical refractory bushing of insulating material surrounding and enclosing the electrodes, a casing surrounding said refractory bushing, and means for securing said casing in position and causing it to support said bushing and electrodes.

11. The combination with a tank to contain molten glass, said tank comprising a bottom consisting of electrically insulating refractory material and formed with an outlet opening extending therethrough, of a pair of electrodes beneath and in register with said opening and arranged to provide a comparatively long narrow channel of about the same cross-sectional area as that of the outlet opening, means for electrically insulating the electrodes from each other, and means for causing an electric current to flow from one electrode to another through a stream or molten glass issuing from said outlet, said insulating means comprising relatively narrow spaces between the electrodes and extending in the direction of the stream flow.

GAMES SLAY'I'ER. 

